I bought a Racing Exhaust Header last week, arriving tomorrow. The problem was the recalled OEM exhaust manifolds, you know the ones that crack and are displayed on your dash via CEL. Anyway after, searching high and low could not find one less than $100 used or $200 new. So, I bought the Header. It has two O2 ports for sensors, but, isn't the OEM manifold attached to a "pre-Cat"? The new header does not have one.